Shell carrier mechanism for automatic shotguns



SHELL CAQRIER MECHANISM FOR AUTOMATIC SHOTGUNS Filed Oct. 7, 1954 M y 1957 E. P. SIMMONS 3 Sheets-Sheet 1 a a m a f r A May 14, 1957 E. P. SIMMONS SHELL CARRIER MECHANISM FOR AUTOMATIC SHOTGUNS Filed Oct. 7, 1954 3 She ets-Sheet 2 May 14, 1957 E. P. SIMMONS SHELL CARRIER MECHANISM FOR AUTOMATIC SHOTGUNS Filed Oct. 7, 1954 3 Sheets-Sheet 5 INVENTOR. [r/zcaf B J7/770200J BY I i fiwm Eyel United States Patent Ofitice 2,791,855 Patented May 14, 1957 SHELL CARRIER MECHANISM FOR AUTOMATIC SHOTGUNS Ernest P. Simmons, Kansas City, Kans., assignor to Olin Mathieson Chemical Corporation, a corporation of Virginia Application October 7, 1954, Serial No. 460,906

Claims. (Cl. 42-17) This invention relates to new and useful improvements in shotguns, and has particular reference to the shell carrier mechanisms of automatic shotguns.

In automatic shotguns, after the gun is fired, the bolt is unlocked and forced rearwardly by the recoil force of the explosion, compressing a closing spring. During the rearward movement of the bolt, it extracts the casing of the exploded shell from the chamber, and ejects it through an opening provided therefor in the receiver portion of the gun. Also as the bolt moves rearwardly, a new shell is fed from a magazine onto a carrier which is disposed beneath and just to the rear of the chamber, within the receiver. The carrier is disposed in a bottom opening formed in the carrier, through which access may be had to the magazine for loading new shells therein when the carrier is raised. When the bolt starts its forward travel under the impetus of the closing spring, it functions through an operative connection to the carrier to flip the carrier upwardly, whereby the new shell carried thereby is elevated into the path of the bolt. The bolt then carries the shell forwardly into the chamber in readiness for the next shot.

In certain well known guns of this general type, there is provided a carrier lock mounted in the receiver and resiliently urged toward a position engaging the carrier to prevent upward movement of said carrier. Said carrier lock is disposed adjacent the carrier in such a position that each new shell fed to the carrier from the magazine engages and moves the lock to an inoperative position. However, when the magazine is empty and the last shell is fired, said lock remains in its operative position, locking the carrier against upward movement. Acting through the operative connection to the bolt, the look also secures the bolt in its rearwardposition, leaving the ejection opening unobstructed. The chamber may then be'reloaded through said ejection opening, after which the carrier lock may be manually released by means of an external button to permit the forward movement of the bolt.

The above structure, which is well known, is subject to a substantial disadvantage. The carrier lock operates to secure the carrier against movement when the gun is closed, and the carrier must be moved in order to reload the magazine, since said carrier normally obstructs the opening to the magazine. Hence the carrier lock must be released manually before each shell can be inserted into the magazine. This operation requires considerable dexterity and is quite inconvenient, since the gunner is normally at that time already using one hand to hold the gun and the other to handle the shells.

The principal object of this invention is, therefore, the provision of means whereby the above disadvantage is eliminated, this object being accomplished generally by means. rendering said carrier lock inoperative whenever thegun isclosed. 1 Another object is the provision, in a gun structure of the class described, of a cam member associated with the of said bolt, said cam member being operable during the final portion of said closing movement to engage and move said carrier lock to an inoperative position. This does not interfere with the primary function of the carrier lock, which is to secure the gun open when all of the shells contained thereby have been fired, but nevertheless permits the magazine to be loaded through the carrier opening at any time the gun is closed.

Other objects are simplicity and economy of construction, and easy adaptability for use with pro-existing guns, with a minimum of alteration.

With these objects in view, as well as other objects which will appear in the course of the specification, reference will be had to the drawing, wherein:

Fig. 1 is a fragmentary side elevational view, with parts broken away, of a shotgun embodying the present invention, with the parts in position for firing, and with the magazine fully loaded.

Fig. 2 is an enlarged fragmentary view similar to Fig. 1, but with different parts thereof broken away.

Fig. 3 is a view similar to Fig. 2, but with the parts shown in the position taken after the last shot has been bolt and movable therewith during the closing movement fired, with the bolt locked in its open position.

Fig. 4 is a slightly irregular sectional view taken on line IVIV of Fig. 3.

Fig. 5 is a sectional view taken on line VV of Fig. 2.

Fig. 6 is a sectional view taken on line VI.-VI of Fig. 2.

Fig. 7 is a sectional view taken on line VII-VII of Fig. 2.

Fig. 8 is a fragmentary sectional view, with parts broken away, taken on line VIII-VIII of Fig. 7.

Fig. 9 is an external side elevational view of the receiver portion of the gun.

Like reference numerals apply to similar parts throughout the several views, and the numeral 2 applies to the receiver portion of an automatic shotgun of the split chamber type, said receiver being elongated longitudinally of the gun and having right and left side Walls 4 and 6, top wall 8, and being open at the bottom. The rearward portion of the bottom opening is closed by a trigger frame 10 secured in the receiver by an assembly pin 12, and the forward portion of said bottom opening forms a carrier opening through which the magazine may be loaded, as will be more fully described. The gun barrel 14 is threaded into the forward end of the receiver, and communicates therewith. A magazine tube 16 is dis posed beneath and parallel to the barrel, and is also threaded at its rearward end into the receiver in communicating relationship therewith. A spring follower cup '18 carried in said magazine tube, and urged rearwardly by a compression spring 20, serves to urge shells 22 in said magazine rearwardly into the receiver.

Carried for longitudinal sliding movement in the rearward end portion of barrel 14 is a tubular shell chamber 24 adapted to receive a shell 22 as shown in Fig. 1. As best shown in Figs. 2 and 3, said chamber is provided at its rearward end with an internal shoulder 26 against which the rim 28 of the shell seats, and an external shoulder 30 which normally abuts the rearward end of the barrel. The chamber is provided with a rearward extension 32 having the form generally of a downwardly opening semi-cylinder. The rearward end of said extension terminates in spaced relation to a for wardly facing shoulder 34 formed internally in receiver 2 As best shown in Figs. 2 and 6, a pin 36 is carried slidably in a bore 38 formed in the wall of said extension, and is urged rearwardly against shoulder 34 by a compression .spring 40 carried in said bore. The-chamshoulder 30 is thus urged forwardly'at all times toward engagement with the rearward end of the barrel.

The bolt. 42, when the: gun is closed, is disposed within I firing pin 48 therein. Said firing pin is urged rearwardly in said bolt against a stop pin 50 by a spring 52, so that the forward end thereof is disposed rearwardly of the forward end of the bolt, and the rearward end thereof projects rearwardly from the back end of the bolt. This structure is best shown in Figs. 1 and 8. When the hammer strikes the rearward end of the firing'pin, as will be described, said firing pin is driven forwardly and the forward end thereof detonates the shell 22 inthe chamber in the usual manner. Said bolt also carries an extractor 54 which functions in the usual manner to engage the rim of the shell in the chamber, and to draw it from the chamber when the bolt moves rearwardly as the gun opens.

The bolt is supported in the receiver by a horizontal pin 55 extending transversely of the gun, passing through respectively on receiver walls 4 and 6 and engaging .notches 106 formed in the edges of the carrier (see Fig.

A carrier lock 108- comprises a substantially flat bar disposed parallel to and just above the normal lowered position of carrier 90, and disposed in a groove 110 formed internally in right side wall 4 of the receiver. It is piv- V oted on a vertical pin 112 threaded in said side wall, said pivot pin being disposed intermediate the ends of the lock bar. Said lock bar is pivotally movable from a position lying substantially entirely Within groove 110, which will be termed its inoperative position, to a position wherev in the rearward end portion thereof projects inwardly a pair of matching slots 56 formed in a pair of side walls 58 and 60 which are integral with the bolt. The forward end portions of said slots, in which pin 55 is disposed when the bolt is closed, are substantially horizontal. The rearward portions of said slots are inclined upwardly and rearwardly, as best shown in Figs. 2 and 8, for a purpose which will appear. Pin 55 extends outwardly from the sides of the bolt, and are carried respcctively in right and left slides 62 and 64. Said slides are mounted respectively for front and rear sliding movement in grooves 66 and 68 which are formed respectively in the internal surfaces of receiver walls 4 and 6. The right slide 62 is provided with a thumb-piece 70 which projects outwardly through a slot 72 formed in receiver wall 4, whereby the slide may be operated manually. Slot 72 is provided at it forward end portion with an upward enlargement 74 which registers substantially with the closed position of the bolt, and which may be termed the ejection opening.

A link 76 is pivoted at its forward endon'pin '55 between the bolt side walls 58 and 60, and extends 'r'ear wardly through the receiver. At its rearward end, it is pivoted as at 78 to an inertia rod 80 which is carried for longitudinal sliding movement in a tubular extension 82 of the receiver, said extension being disposed 'in the stock 84 of the gun. Within said extension, a collar 86 on said rod is engaged by a closing spring'SS, whereby the inertia rod and link 76 are urged forwardly to hold the bolt in its closed position.

A shell carrier 90 having the form of a fiat bar with the upper surface thereof cylindrically curved is disposed in the lower forward portion of the receiver, substantially in alignment with magazine tube 16, so as to receive thereon each shell as it is ejected from the magazine by spring 20. It is provided at its rearward end with an upstanding wall 92 which serves to arrest "the rearward movement of a'shell thereon. Said carrier is supported by a. rearwardly extending integral arm 94 which extends along the right side of trigger frame 10, and which is mounted on a horizontal transverse pin 96 which is pivoted in frame 10. Said arm extends re'ar- I wardly from pin 96, and a pawl 98 is pivoted to the rearward end thereof at 100. A single spring 102 serves both to urge pawl 98 upwardly and forwardly to the position shown in Fig. 2, and to urge carrier 90 downwardly. The downward movement of the carrier is limited by a pair of inwardly projecting lugs 104iformed into the receiver, which will be termed its operative position. In the operative position, a finger 114 formed by the rearward end of the lock bar 108 overlaps on upwardly facing shoulder 116 formed on carrier arm 94, and rest against a stop 118 which rises from said shoulder. The lock bar is urged toward it operative position by'a compression spring 120 disposed between the lock bar and receiver wall 4 (see Fig. 4). The carrier lock may be manually moved to its inoperative position by means of a push button 122 fixed thereto and projecting outwardly through a hole 124 formed in receiver wall 4. The carrier lock bar is provided at its forward end with an inwardly turned tooth 126. When the lock is in its operative position, as in Fig. 4, said tooth is positioned entirely within groove 110. When the lock is moved toward its inoperative position, as in Fig. 5, tooth 126 projects inwardly behind the magazine to prevent more than one shell at a time from leaving the magazine, as will be described.

The structure thus far described is well-known, and the operation thereof is substantially as follows: Assuming first that the gun is in position for firing, with extra shells in the magazine, the parts have the position shown in Figs. 1 and 2. It will be noted that the rearmost shell in the magazine abuts at its rearward end against the beveled forward end of the carrier 90, which tends to elevate the shell slightly, and against the inclined lower end of a tang .128 integral with and depending from bolt 42, and is thereby prevented from moving rearwardly onto the carrier.

The trigger and hammer mechanism carried by frame 10 forms no part of the present invention, and need not here be described in detail. It is believed sufiicient to state that when the trigger 130 is pulled rearwardly, it moves on its pivot 132 (see Fig. 1), so that the forwardly projecting toe 134 is lowered out of the sear notch 136 of hammer .138, which is pivoted at 140 in frame 10. The hammer, thus freed, is pivoted upwardly and forwardly by spring 142 to strike the rearward end of fi.r ing pin 48 to detonate shell 22 in the chamber, as previously described. The hammer moves through a longitudinalslot 143 formed in link 76. The first recoil shock of the explosion drives bolt 42, chamber 24 and chamber extension v3:2 rearwardly as a unit, since the bolt is locked :in said extension by lug 44. This initial movement is also transmitted through pin 55 to slides 62 and 64, link 76, and inertia rod 80. The movement of the chamber and extension thereof is arrested by engagement with receiver shoulder 34, but the rearward movement of pin 55, slides 62 and 64, link 76, and inertia-rod 80 continues, due to the momentum applied thereto during. the chamber movement. vAfter a very 'slightdelay, during which pin '55 traverses the horizontal portions of bolt slots 56, said pin enters the inclined portions of said slots. The engagement of the pin with the inclined walls o'f slots 56 then earns the rearward end of'the bolt downwardly, "extracting locking lug 44 thereof out of chamber extension slot 46. With the'bolt thus unlocked,

it is forced rearwardly in the receiver by the residual As the bolt moves rearwardly, extractor 54 pulls shell '22 out of the chamber, and as the bolt reaches the rearward limit of its travel, as shown in Fig. 3, an ejector, not shown, engages said shell and flips it to the right through ejection opening 74. Also, as the bolt moves rearwardly and hence moves tang 128 thereof out of the path of the rearmost shell 22 in the magazine, said shell will be forced rearwardly onto carrier 90 by magazine spring 20, until it is stopped by rear wall 92 of the carrier. As said shell moves rearwardly, the rim thereof moves along the inner surface of carrier lock bar 108, forcing said bar outwardly to its inoperative position within receiver groove 110.

As the bolt moves rearwardly, it enters between and is guided by the top wall 8 of the receiver and a pair of tracks 144 formed on trigger frame 10 and disposed parallel to the receiver top wall. The bolt lug 44 engages the top wall and the bolt side walls 58 and 60 engage tracks 144. During the final portion of the rearward movement of the bolt, the rearward edge of the right side wall 58 of the bolt contacts pawl 98 and pivots said pawl rearwardly and downwardly, against the pressure of spring 102. The lower edge of said side Wall then rides over the pawl until the toe 146 of said pawl snaps upwardly into engagement with a notch 148 formed in the lower edge of side wall 58.

The pawl and bolt then have the position shown in Figs. 2 and 3, the bolt being urged forwardly against the pawl by closing spring 88, but it will be recalled that the carrier lock 108 is at this time being held in its inoperative position by the shell 22 on carrier 90. Since the line of force of the bolt on the pawl, which extends from the notch 148 through pawl pivot 100, passes below carrier pivot 96, the first forward movement of the bolt causes the pawl and the rearward portion of carrier arm 94 to act as a toggle, buckling the pivot 100 downwardly and forcing carrier 90 upwardly, thereby moving the shell 22 carried thereby upwardly into chamber extension 32, in the path of the bolt. As the carrier moves upwardly, the carrier lock is retained in its inoperative position by its engagement with the side edge of the carrier. At this time, the tooth 126 of the carrier lock is disposed behind the magazine to prevent the next shell in the magazine from being projected outwardly therefrom. The bolt then continues its forward movement to push shell 22 into the chamber to ready the gun for the next shot, the bolt lug 44 being cammed upwardly into chamber extension slot 46 by pin 55, and the hammer 138 having been cocked by link 76 during the rearward stroke of the bolt.

However, on the last shot, with the magazine empty, no shell is positioned on the carrier to hold the carrier lock in its inoperative position, as shown in Figs. 3 and 4, locking said carrier against upward movement. Hence when the bolt reaches the rearward end of its travel and notch 148 thereof engages pawl toe 146, said bolt cannot move forwardly, since such movement is necessarily accompanied by upward movement of the carrier. A shell may then be manually inserted into the chamber 24, and the gun permitted to close by pressing push button 122, which moves the carrier lock to its inoperative position. The magazine may then be loaded by holding push button 122 in manually, pressing shells successively against the lower surface of carrier 90 to pivot said carrier upwardly until the forward end of the shell registers with the magazine, then pushing the shell forwardly into said magazine. The shell rims may be pushed past the carrier lock tooth 126 even though the lock is necessarily at this time in its inoperative position. This is accomplished by a slight resilient deformation of the lock bar by the pressure exerted normally on the shell. However, the tooth snaps into place behind each shell, and will not permit rearward movement thereof.

As previously stated, the structure and operation thus far described is well known, and no claim is made thereto as such. My invention consists of the combination with such previously described structure of means for automatically rendering the carrier lock inoperative whenever the gun is closed. As described above, with the present structure the lock is operative whenever the gun is closed, and thus it is necessary to hold push button 122 in manually to load the magazine. As pointed out, this is very inconvenient since both of the operator's hands are normally otherwise occupied.

Structurally, my invention consists of the bevelling of the inner surface of the lower forward corner portion of right slide 62 to form a cam surface 150 (see Figs. 5 and 8), and the addition of a cam follower bar 152 fixed to the forward portion of carrier lock bar 108 and extending upwardly therefrom into the receiver slide groove 66. It will thus be apparent that as the slide 62 and bolt 42 reach their forward or closed position, the final portion of said movement will cause cam 150 to engage follower bar 152 and move it inwardly, as best shown in Fig. 5, thereby moving it to an inoperative position and permitting the magazine to be loaded without pressing push button 122.

It is obvious that if desired cam 150 could be so proportioned as to cam the carrier lock bar 108 all the way into its receiver groove 110. However, it would then be possible, if the parts were not perfectly fitted, that the follower bar would arrest the forward movement of slide 62, and hence of the bolt, before the bolt was fully locked. It has therefore been found desirable to provide that cam 150 shall move the carrier lock only partially toward its groove, as shown in Fig. 5. The finger 114 of the lock bar is hence still disposed over the shoulder 116 of the carrier. The edge of said shoulder is then bevelled as at 154. When the carrier is pressed upwardly as in loading the magazine, bevel 154 engages and cams the finger 114 outwardly to permit the carrier to pass. The carrier lock is hence actually rendered inoperative when it has been moved to the position shown in Fig. 5.

My cam and follower do not in any way interfere with any essential feature of operation of the carrier look as it has previously been used. Said lock still performs its primary function of holding the bolt open after the final shot. Also, my cam and follower operate only during the terminal portion of the forward movement of the bolt. After the carrier moves down to its normal position after each operation, the lock moves momentarily to its operative position before cam 150 engages and moves it to an inoperative position. This momentary movement is necessary since it is at that time that lock bar tooth 126 moves outwardly to permit the next shell in the magazine to move rearwardly therefrom.

While I have shown and described a specific embodiment of my invention, it is evident that many minor changes of structure and operation could be made without departing from the spirit of the invention as defined by the scope of the appended claims.

What I claim as new and desire to protect by Letters Patent is:

l. A shotgun including a receiver open at the bottom, a barrel communicating with said receiver and having a shell chamber at its rearward end, a magazine tube beneath said barrel and communicating at its rearward end with said receiver, a bolt carried in said receiver and movable by recoil from a closed position abutting a shell in said chamber to a rearward or open position, a carrier movably supported in said receiver and normally positioned to receive shells from said magazine, and normally obstructing the bottom opening of said receiver, a closing spring urging said bolt toward its closed position, an operative member carried by said carrier and engageable by said bolt in its open position, said member being oper able during the initial portion of the closing movement of said bolt to move said carrier upwardly to place the shell carried thereby in the path of said bolt, whereby said shell is carried into said chamber, a carrier lock mounted movably in said receiver adjacent said carrier, means normally urging said lock into an operative position in engagement with said carrier whereby to prevent movement to engage said cam follower and move said lock to, an inoperative position, whereby when said gun is closed said carrier may be manually raised to clear said bottom receiver opening to permit loading of said magazine therethrough.

2 The structure as set forth in claim 1 wherein said earn member constitutes one of a pair of" slides disposed respectively at opposite sides of said bolt and carried in grooves formed, interiorly in said receiver longitudinally of said gun, said slides supporting said bolt.

3. The structure as set forth in claim 1 wherein said carrier look comprises, a lock bar pivoted in a wall of said receiver for movement in a horizontal plane, the rearward end of said bar being positioned, when in its operative position, to extend, inwardly into said receiver and to overlap an upwardly facing shoulder formed on said carrier, whereby to prevent upward movement of said carrier, and wherein said cam member and cam follower operate to pivot said lock bar to an inoperative position relative to said carrier shoulder.

4. The structure as set forth in claim 1 wherein said carrier lock comprises a lock bar pivoted in a wall of said receiver for movement in a horizontal plane, the rearward end of said bar being positioned, when in its operative position, to extend inwardly into said receiver audio. over a anupwa l f siag. sh ude ormed on a rr e hereby to P ev u r mo men aid carrier, and wherein said cam member and cam follower operate to pivot said lock bar outwardly only a portion of the width of said carrier shoulder, wherebywhen the bolt is closed said lock bar still overlaps said shoulder, the portion-of the shoulder then under the lock bar being'bevel'led, whereby when the carrier is moved manual- 1y upwardly, the bevel-led portion of said shoulder will engage and; earn said lock bar outwardly to permit movement of said carrier past said 1001; bar.

5. The structure as set forth in claim 1 wherein said carrier lock comprises an elongated lock bar pivoted intermediate is front and rear ends in a wall of said reeeiver for movement in a horizontal plane, the rearward end of said bar, when in its operative position, extending into the receiver to engage and prevent upward movement of said carrier, and the forward end of said bar being provided with a tooth which, when the bar is in its inoperative position, extends inwardly behind said magazine to prevent movement of shells therefrom, said operative member carried bysaid carrier being disengageable from said bolt during the closing movement thereof, therebypermitting the return of said carrier to its normal posit-ionQand the movement of said lock to its operative position, before said cam operates to return said lock to its inoperative position.

ReferencesvCited in'the file of this, patent UNITED STATES PATENTS 

